tire clearance in brakes

[driftlessregion]

I'm frustrated with having to let out the air in my tires  in order to get them past the brake pads. The tires are 28s and the brakes are the original Shimano new in about 2000 medium reach calipers. They just don't far enough. I ride 28 every day. I can push the 28s past the pads but not the 32s I put on for touring. I'm contemplating removing them for cantilevers but before I do I'm wondering if any other calipers of that quality do open farther?

[dkoloko]

Do the brakes have quick release? Do you have posts for cantilevers?

[driftlessregion]

Yes they have quick releases but they don't open like the brakes of old. I will add posts if I go that route. Easy to do.

[mjcambron]

What rims are you using?  You might have particularly narrow rims that were designed for 20-23mm tires...  If you can't clear the tire after opening the QR, have you considered adjusting the cable such that you need to crank the adjusting barrel a few turns.  Perhaps the combination of QR + adjusting barrel will provide a satisfactory solution.
Cheers,
mike 

[John Nelson]

Also, make sure you're not using an incompatible tire/rim combination. To use a 32 mm tire, you should have a rim size between 15 mm and 19 mm (inner rim width measured between the ends of the hooks). A lot of rims are only 13 mm.